RESUMO
BACKGROUND: During the masticatory cycle, loads of different intensities and directions are received by the dental structures and/or implants, which can cause micromovements at the junction between the abutment and implant. OBJECTIVE: The objective of this in vitro study was to evaluate the behavior of three different implant connections subjected to different load values using a digital radiography system. Additionally, the torque values for removing the abutment screws were also measured and compared. METHODS: Ninety sets of implant and abutment (IA) were used, divided into three groups according to the type of connection (n = 30 per group): EH group, external hexagon type connection; IH group, internal hexagon connection; and, MT group, Morse taper connection. RESULTS: MT group showed the better vertical misfit behavior at the three intensity of load applied, in comparison with EH and IH groups. In the analysis of torque maintenance (detorque test), MT group showed higher values of detorque when compared with the measured values of EH and IH groups (p < 0.001). CONCLUSIONS: The IA sets of EH and IH groups showed a microgap in all levels of applied loads, unlike the MT group this event was not observed. In the detorque test, MT group increase in the torque values when compared to the initial torque applied, unlike EH and IH groups showed a decrease in the initially torque applied in all conditions tested. A positive correlation was detected between the misfit and detorque values.
Assuntos
Coroas , Implantes Dentários , Dente Suporte , Projeto do Implante Dentário-Pivô , Análise do Estresse Dentário , Próteses e Implantes , TorqueRESUMO
Different surgical treatment strategies for peri-implantitis with the use of graft material and membranes have been suggested without any longitudinal remarkable success rate. The present preliminary study was aimed to analyze a new clinical approach based on the disinfection of the implant connection, the disinfection of the implant surface and GBR approach in the treatment of circumferential and semi-circumferential bony defect resulting from peri-implantitis. Six consecutive patients were selected for the present study. After removal of factors that could potentially influence peri-implant pathology, the prosthetic rehabilitation was always removed and a full thickness flap was elevated to allow access to the peri-implant defect and the exposed implant surface. Once the defect was degranulated and the implant surface cleaned, a mixture (50:50) of autogenous bone and allograft was used. Guided bone regeneration technique using membranes was adopted and the flaps were closed for a submerged healing. Six months thereafter, a new re-opening procedure was performed and cleaned superstructures and crowns were repositioned. Patients were followed for one year thereafter and recalled for a customized oral hygiene every three months. Radiological and periodontal analysis was performed before surgery and every six months. The studied procedure was associated with a pronounced increase in REC and CAL with stable peri-implant conditions at 6 and 12 months. PI, BOP and PD values were significantly reduced both at 6 and 12 months. At 12 months, a mean PD gain of 4.5 mm and a bone loss reduction of 5.1 mm was obtained. Within the limitation of the present preliminary study, the proposed technique might represent a promising result for treatment of circumferential and semi-circumferential bone defects around implants affected by peri-implantitis.
Assuntos
Implantes Dentários , Desinfecção/métodos , Peri-Implantite/cirurgia , Regeneração Óssea , Prótese Ancorada no Osso , Seguimentos , Humanos , Peri-Implantite/diagnóstico por imagem , Estudos Prospectivos , Radiografia Dentária , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Propriedades de Superfície , Fatores de Tempo , Resultado do TratamentoRESUMO
Abstract Different surgical treatment strategies for peri-implantitis with the use of graft material and membranes have been suggested without any longitudinal remarkable success rate. The present preliminary study was aimed to analyze a new clinical approach based on the disinfection of the implant connection, the disinfection of the implant surface and GBR approach in the treatment of circumferential and semi-circumferential bony defect resulting from peri-implantitis. Six consecutive patients were selected for the present study. After removal of factors that could potentially influence peri-implant pathology, the prosthetic rehabilitation was always removed and a full thickness flap was elevated to allow access to the peri-implant defect and the exposed implant surface. Once the defect was degranulated and the implant surface cleaned, a mixture (50:50) of autogenous bone and allograft was used. Guided bone regeneration technique using membranes was adopted and the flaps were closed for a submerged healing. Six months thereafter, a new re-opening procedure was performed and cleaned superstructures and crowns were repositioned. Patients were followed for one year thereafter and recalled for a customized oral hygiene every three months. Radiological and periodontal analysis was performed before surgery and every six months. The studied procedure was associated with a pronounced increase in REC and CAL with stable peri-implant conditions at 6 and 12 months. PI, BOP and PD values were significantly reduced both at 6 and 12 months. At 12 months, a mean PD gain of 4.5 mm and a bone loss reduction of 5.1 mm was obtained. Within the limitation of the present preliminary study, the proposed technique might represent a promising result for treatment of circumferential and semi-circumferential bone defects around implants affected by peri-implantitis.
Assuntos
Humanos , Implantes Dentários , Desinfecção/métodos , Peri-Implantite/cirurgia , Propriedades de Superfície , Fatores de Tempo , Regeneração Óssea , Radiografia Dentária , Estudos Prospectivos , Reprodutibilidade dos Testes , Seguimentos , Resultado do Tratamento , Estatísticas não Paramétricas , Peri-Implantite/diagnóstico por imagem , Prótese Ancorada no OssoRESUMO
UNLABELLED: Although the use of zirconia abutments for implant-supported restorations has gained momentum with the increasing demand for esthetics, little informed design rationale has been developed to characterize their fatigue behavior under different clinical scenarios. However, to prevent the zirconia from fracturing, the use of a titanium connection in bi-component aesthetic abutments has been suggested. OBJECTIVE: Mechanical testing of customized thin-walled titanium-zirconia abutments at the connection with the implant was performed in order to characterize the fatigue behavior and the failure modes for straight and angled abutments. MATERIAL AND METHODS: Twenty custom-made bi-component abutments were tested according to ISO 14801:2007 either at a straight or a 25° angle inclination (n=10 each group). Fatigue was conducted at 15 Hz for 5 million cycles in dry conditions at 20°C±5°C. Mean values and standard deviations were calculated for each group. All comparisons were performed by t-tests assuming unequal variances. The level of statistical significance was set at p≤0.05. Failed samples were inspected in a polarized-light and then in a scanning electron microscope. RESULTS: Straight and angled abutments mean maximum load was 296.7 N and 1,145 N, the dynamic loading mean Fmax was 237.4 N and 240.7 N, respectively. No significant differences resulted between the straight and angled bi-component abutments in both static (p=0.253) and dynamic testing (p=0.135). A significant difference in the bending moment required for fracture was detected between the groups (p=0.01). Fractures in the angled group occurred mainly at the point of load application, whereas in the straight abutments, fractures were located coronally and close to the thinly designed areas at the cervical region. CONCLUSION: Angled or straight thin-walled zirconia abutments presented similar Fmax under fatigue testing despite the different bending moments required for fracture. The main implication is that although zirconia angled or straight abutments presented similar mechanical behavior, the failure mode tended to be more catastrophic in straight (fracture at the cervical region) compared to angled abutments.
Assuntos
Dente Suporte , Projeto do Implante Dentário-Pivô , Materiais Dentários/química , Titânio/química , Zircônio/química , Implantes Dentários , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Estresse MecânicoRESUMO
PURPOSE: To analyze the interleukin (IL)-1ß and IL-10 expressions in periimplant crevicular fluid (PICF) in healthy and diseased regions to elucidate the inflammatory process around implants and its influence on clinical diagnosis. MATERIALS AND METHODS: PICF samples from 30 patients were analyzed for IL-1ß and IL-10 concentrations by enzyme-linked immunosorbent assay. Patients were divided in Groups A (health), B (mucositis), and C (periimplantitis). Plaque accumulation, periodontal phenotype (PP), depth on probing, and history of periodontitis (HP) were evaluated. RESULTS: IL-1ß levels were lower in healthy group compared with Groups B (P < 0.0005) and C (P < 0.001). IL-10 levels were higher in Groups A compared with B (P = 0.033) and C (P = 0.0001). Patients with HP and thin PP had 9 and 4.5 times more chance of presenting disease, respectively. CONCLUSIONS: Lower IL-1ß and higher IL-10 levels characterized healthy periimplant conditions, which demonstrate the anti-inflammatory predominance in sites without disease signs. IL-10 levels decrease significantly according to increase of disease status. Therefore, its levels can differentiate healthy, mucositis, and periimplantitis. Thin PP and HP are associated with periimplant disease. These findings suggest the use of ILs as a biochemical marker for early diagnosis of periimplant disease.
Assuntos
Implantes Dentários , Líquido do Sulco Gengival/imunologia , Interleucina-10/análise , Interleucina-1beta/análise , Peri-Implantite/imunologia , Estomatite/imunologia , Adulto , Idoso , Biomarcadores/análise , Periodontite Crônica/imunologia , Índice de Placa Dentária , Falha de Restauração Dentária , Feminino , Seguimentos , Gengiva/patologia , Humanos , Mediadores da Inflamação/análise , Masculino , Pessoa de Meia-Idade , Osseointegração/fisiologia , Índice Periodontal , Bolsa Periodontal/classificação , Bolsa Periodontal/imunologia , Periodonto/patologia , FenótipoRESUMO
Although the use of zirconia abutments for implant-supported restorations has gained momentum with the increasing demand for esthetics, little informed design rationale has been developed to characterize their fatigue behavior under different clinical scenarios. However, to prevent the zirconia from fracturing, the use of a titanium connection in bi-component aesthetic abutments has been suggested. Objective: Mechanical testing of customized thin-walled titanium-zirconia abutments at the connection with the implant was performed in order to characterize the fatigue behavior and the failure modes for straight and angled abutments. Material and Methods: Twenty custom-made bi-component abutments were tested according to ISO 14801:2007 either at a straight or a 25° angle inclination (n=10 each group). Fatigue was conducted at 15 Hz for 5 million cycles in dry conditions at 20°C±5°C. Mean values and standard deviations were calculated for each group. All comparisons were performed by t-tests assuming unequal variances. The level of statistical significance was set at p≤0.05. Failed samples were inspected in a polarized-light and then in a scanning electron microscope. Results: Straight and angled abutments mean maximum load was 296.7 N and 1,145 N, the dynamic loading mean Fmax was 237.4 N and 240.7 N, respectively. No significant differences resulted between the straight and angled bi-component abutments in both static (p=0.253) and dynamic testing (p=0.135). A significant difference in the bending moment required for fracture was detected between the groups (p=0.01). Fractures in the angled group occurred mainly at the point of load application, whereas in the straight abutments, fractures were located coronally and close to the thinly designed areas at the cervical region. Conclusion: Angled or straight thin-walled zirconia abutments presented similar Fmax under fatigue testing despite the different bending moments required for fracture...
Assuntos
Humanos , Dente Suporte , Planejamento de Prótese Dentária , Materiais Dentários/química , Titânio/química , Zircônio/química , Implantes Dentários , Falha de Restauração Dentária , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Estresse MecânicoRESUMO
Verificar a perda óssea radiográfica ao redor dos implantes de largo diâmetro quando implantes de diâmetro estreito/convencional são usados no mesmo estudo. Métodos: uma busca eletrônica feita entre os anos de 1966 e 2012 no PubMed/Medline, combinando as palavras-chave dental implants, wide diameter, wide body, large platform, large diameter e wide platform, foi realizada. Na primeira fase, 486 artigos foram recuperados para análise preliminar do título e dos resumos até 1º de março de 2012. Na segunda fase (60 artigos), estudos laboratoriais, modelos animais, estudos de casos e séries de casos com menos de um ano de acompanhamento foram excluídos. O desfecho primário foi a mensuração da perda óssea radiográfica. Resultados: sete estudos (dois prospectivos, dois RCT prospectivos, três retrospectivos) foram selecionados. Os diâmetros dos implantes variaram de 3,5 mm a 8,0 mm. Em geral, os valores de perda óssea para os implantes estreitos/convencionais e de largo diâmetro foram menores do que 2,0 mm, tanto nos estudos prospectivos (faixa um/três anos) como nos retrospectivos (faixa um/seis anos). Dois estudos retrospectivos atribuíram as diferenças observadas às curvas de aprendizagem e desenhos dos implantes. Ainda, dois estudos prospectivos demonstraram os benefícios dos protocolos plataforma switching (4,1/5,0 mm) na redução da perda óssea pelo menos um ano depois. Um RCT não demonstrou diferenças significativas (um ano de acompanhamento; implantes de 8 mm versus implantes de 4 mm de diâmetro). A maioria dos implantes foi inserida com protocolo de dois estágios e em sítios já cicatrizados. Conclusão: dentro dos limites desta revisão, a perda óssea radiográfica ao redor dos implantes de largo diâmetro não difere dos implantes estreitos/convencionais, quando comparada para a mesma população de pacientes...
To verify radiographic bone loss levels around wide-body dental implants when narrow/or standard ones are used in the same study. Methods: an electronic search between the years of 1966 to 2012 was made on the PubMed/Medline database combining the keywords dental implants, diameters, wide diameter, wide body, large platform, large diameter, and wide platform. In the first phase, four-hundred and eight-six articles were retrieved for preliminary title and abstract analyses until March 1st, 2012. In the second phase (60 articles), no laboratory, animal, case studies, or clinical studies with less than one-year of follow-up were included. The primary outcome was radiographic bone loss measurement. Results: seven studies (two prospective, two prospective RCTs, three retrospective) were selected. Implant diameters varied from 3.5 mm to 8.0 mm. Overall mean bone loss values for narrow/standard and wide diameters were less than 2.0 mm in both prospective (range: 1-3 years) and retrospective (range: 1-6 years) trials. Two retrospective studies attributed the observed differences due to learning curves and implant designs. Also, two prospective studies demonstrated the benefi ts of platform switching protocols (4.1/5.0 mm) in reducing bone loss at least one year later. One RCT demonstrated no significant differences (1 year of follow-up; 8 mm - versus 4 mm - diameter fi xtures). Most implants were inserted with a two-stage technique and at healed sites. Conclusions: within the limits of this review, radiographic bone loss around wide diameter implant does not differ from narrow/standard diameters in the same patient population...
Assuntos
Humanos , Perda do Osso Alveolar , Implantes DentáriosRESUMO
PURPOSE: This prospective randomized matched-pair controlled trial aimed to evaluate marginal bone levels and soft tissue alterations at implants restored according to the platform-switching concept with a new inward-inclined platform and compare them with external-hexagon implants. MATERIALS AND METHODS: Traditional external-hexagon (control group) implants and inward-inclined platform implants (test group), all with the same implant body geometry and 13 mm in length, were inserted in a standardized manner in the posterior maxillae of 40 patients. Radiographic bone levels were measured by two independent examiners after 6, 12, and 18 months of prosthetic loading. Buccal soft tissue height was measured at the time of abutment connection and 18 months later. RESULTS: After 18 months of loading, all 80 implants were clinically osseointegrated in the 40 participating patients. Radiographic evaluation showed mean bone losses of 0.5 ± 0.1 mm (range, 0.3 to 0.7 mm) and 1.6 ± 0.3 mm (range, 1.1 to 2.2 mm) for test and control implants, respectively. Soft tissue height showed a significant mean decrease of 2.4 mm in the control group, compared to 0.6 mm around the test implants. CONCLUSIONS: After 18 months, significantly greater bone loss was observed at implants restored according to the conventional external-hexagon protocol compared to the platform-switching concept. In addition, decreased soft tissue height was associated with the external-hexagon implants versus the platform-switched implants.
Assuntos
Adaptação Fisiológica/fisiologia , Perda do Osso Alveolar , Remodelação Óssea/fisiologia , Projeto do Implante Dentário-Pivô , Implantes Dentários/efeitos adversos , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/etiologia , Perda do Osso Alveolar/patologia , Fenômenos Biomecânicos , Brasil , Placa Dentária/patologia , Feminino , Seguimentos , Humanos , Itália , Masculino , Análise por Pareamento , Maxila , Pessoa de Meia-Idade , Osseointegração , Estudos Prospectivos , Radiografia , Fumar , Estatísticas não ParamétricasRESUMO
AIM: To evaluate the effect of mismatching abutments on implants with a wider platform on the peri-implant hard tissue remodeling and the soft tissue dimensions. MATERIAL AND METHODS: Mandibular premolars and first molars of six Labrador dogs were extracted bilaterally. After 3 months of healing, one tapered implant was installed on each side of the mandibular molar region with the implant shoulder placed at the level of the buccal alveolar bony crest. On the right side of the mandible, an abutment of reduced diameter in relation to the platform of the implant was used, creating a mismatch of 0.85 mm (test), whereas an abutment of the same diameter of the implant platform was affixed in the left side of the mandible (control). The flaps were sutured to allow a non-submerged healing. After 4 months, the animals were sacrificed and ground sections were obtained for histometric assessment. RESULTS: All implants were completely osseo-integrated. Bone levels were superior at the test than at the control sites. However, statistically significant differences were found only at the buccal and proximal aspects. The soft tissue vertical dimension was higher at the control compared with the test sites. However, statistically significant differences were demonstrated only at the buccal aspects. CONCLUSIONS: A mismatch of 0.85 mm between the implant and the abutment yielded more coronal levels of bone-to-implant contact and a reduced height of the peri-implant soft tissue (biologic width), especially at the buccal aspect, if the implant shoulder was placed flush with the level of the buccal alveolar bony crest.